3mm Extreme Durability Hard Night Dental Guard


3mm Extreme Durability Hard Night Guard is for severe teeth grinding/jaw clenching (bruxism)

Made with dentist-grade hard acrylic-like material, your Sentinel Night Guard is non-flexible and solidly built. Safe for nightly use.
All of our night guard products are BPA, Silicon, Latex and Phthalate free.

  • Custom fit to your unique dental anatomy.
  • Non-flexible. Snaps into place for a perfect fit.
  • Relieves jaw pain, teeth pain, headaches, tooth sensitivity
  • Protects teeth from breakage, cracking, damage
  • Protects veneers, crowns, restorative dental work
  • Combats pain or tenderness of the temporomandibular joints
  • Easy “how to” instructions ensures consistent teeth impression results
  • Excellent durability and clarity.

What You’ll Get

  • A complete impression kit with instructions and prepaid return mailer
  • (1) custom night guard
  • Breathable retainer case
  • Fast all inclusive FREE shipping
  • 1 year warranty

Product Description

Premium 3mm Hard Dental Night Guard for Heavy Duty Teeth Grinding and/or Jaw Clenching

Made with dentist-grade hard acrylic-like material, your Sentinel Night Guard is non-flexible and built for durability. Safe for nightly use. All of our night guard products are BPA, Silicon, Latex and Phthalate free.

If for any reason, you experience pain or discomfort while using your product please discontinue use and contact us. Our commitment to you is 100% satisfaction. We provide free night guard adjustments.


Wake up Smiling or Your Money Back

The Sentinel Guarantee

Located in St. Petersburg, Florida, we specialize in night guard and mouth guard manufacturing.  All of our products are made in the USA by professional lab technicians with a combined dental experience of 20+ years. We guarantee:

    • 100% unconditional money back guarantee. We stand behind our products and will provide you with nothing less than our personal best from our long-standing team.
    • 90 Day Satisfaction Guarantee. If you don’t LOVE your new night guard (whether it’s a fit issue or comfort) let us know within 90 days. We'll either keep working to your satisfaction or you can opt for a refund in full.
    • 1 Year Warranty. If you break or grind through your night guard within 1 year of purchase, we’ll replace it for you free of charge.

Due to its thicker nature, we require that you take upper and lower teeth impressions for an even bite and to ensure proper occlusion.

If for any reason, you experience pain or discomfort while using your product please discontinue use and contact us. Our commitment to you is 100% satisfaction. We provide free night guard adjustments. 90 Day money back guarantee. Free all inclusive shipping in the USA.

.120 (3mm thickness) An added layer of thickness for extra durability. Ideal for severe nighttime grinding or jaw clenching. Suggested for heavy grinders.

Our Commitment To You

The Sentinel warranty and return policy is unlike any other. We stand by our products and will always work with you to your absolute satisfaction. This means if you are dissatisfied with your product for any reason, you can either contact Sentinel within 90 days for a full refund or opt to continue working with us until you get a great fitting guard. No hassle. No jumping through hoops. Our commitment to you is 100% satisfaction.

Get Fitted. Get Protected.

FREE SHIPPING IN THE U.S.A (International customers are responsible for shipping on return mailer).

Additional Information

Weight3 oz


Guard for


Product Reviews

  • Nancy

    BEST MOUTH GUARD I HAVE FOUND! This is a 5 star product, way cheaper than the dentist and fits perfect.

  • Leah Delaney

    After my dentist told me I needed a guard to prevent teeth grinding, he tried to sell me one of his night guards. When that didn’t work because of the astronomical cost of the guard he wanted to sell me, I was then referred to an ENT doctor. I was told to stress less, take magnesium and wear a night guard. I was about to give up when I did a search and selected this company because of the positive reviews. I’m adding another positive review.

    So far, I have had only positive things to say about this experience.

    For this night guard you will need to take upper and lower dental impressions.
    I received the kit quickly and read the instructions thoroughly but I still had a few questions and called the company and customer service was great. My questions were answered.

    I was apprehensive about making the mold. I tried placing the mold tray in my mouth and gagged. The company representative (Suzanne?) told me to use the slightly larger tray because I should not hit the tray with my teeth. They include two tray sizes but an additional size is available should the included ones not fit properly. It’s also important to mix the molding clay properly into a consistent color before inserting into the tray.

    Set a timer for 3 minutes. You need a full 3 minutes with the molding clay/tray in your mouth for the mold to form properly. Try doing this in front of the mirror. If you fail you can call the company and they will supply you another kit at no cost.

    After you make the mold you need to send a photo to sentinelmouthguards@gmail.com and they will confirm whether it is successful before you mail it to the lab in a self-addressed, prepaid envelope.

    It took about 10 days from the date of mailing for the guard to arrive.

    The guard comes with a free retainer case.

    My guard required no additional adjustments but the company will help you should you need it.

    This was my first guard and has worked successfully so far. According to the company, the guard should last about 2 years. They also keep the impressions on file for 1 year from the date of purchase in case you need to reorder.

  • Cristina C.

    I researched a lot of other companies and they didn’t require the upper and lower teeth impressions. I like that they make sure the bite is correct. I was skeptical because it’s so much cheaper than the dentist but I got my guard and waited to weigh in. The guard fits perfect and I’ve been sleeping soundly for several weeks now. This is the real deal. Thank you for existing Sentinel. You’re a tooth saver!

  • Carl S.

    This is the only brand I trust. I’ve been a Sentinel customer for 10 years. Their customer service is great. They’re consistent and I love their night guards. I have a no-show day guard that I wear during the day and the extreme durability guard at night. Nothing less than a positive experience for me. 5 stars!

  • Carol Williams

    I have been having serious grinding issues since being locked at home- my teeth and surrounding areas including my jaw were in real pain every single day. My jaw would painfully pop when I ate anything or dared to open my mouth too wide- I was miserable. Bought way too many over the counter guards with minimal results. First use of the Sentinel guard and immediately noticed less pain- the very first night. I’ve stuck with it and all of my symptoms are near gone. This product works! I won’t be going back to Walgreens. I’m sticking with quality.

  • Jordan Harris

    I have gnawed through several of this online guards from different companies. I was about to pay $1200 at my dentist for a thicker one when I found the Sentinel team and decided to give them a try. The first impressions I thought were okay but they sent new impressions explaining that they needed a really nice impression to make a proper fitting guard. I retook the impressions. They didn’t charge me for the redos. I got the guard back and it fit perfect. So far so good!

  • Kelly L. Beck

    I was a little nervous when I ordered this because similar mouth guards have been uncomfortable, but I thought I would give it a try…what a pleasant surprise they are super comfortable! I ordered both a day guard and this heavy duty one. I love them and would definitely recommend.

  • Mr. Leon

    High quality and beautifully crafted, the 3mm hard guard exceeded my expectations. I especially like that they don’t cut the material straight across. The guard is low profile (it doesn’t extend up over the teeth). I find it comfortable, and the teeth impression process was not too difficult to get done, but i can see that an older person may have trouble because you do have to mix the putty fast and work quickly.

  • Hugh Jordan

    This mouth guard is great. I sometimes use it during the day when I feel a headache coming on. I know I clench my teeth during the day too. Then I just make sure to clean it and put it by my bedside for night use. Cleans very nicely and easy to store. It doesn’t look cheap. This is a really good price for a high quality mouth guard.

  • Gregory Tominaga

    It’s true there really is a learning curve to wearing a strange plastic thing in your mouth at night. However they do get more comfy overtime. Easy to do the putty process. Hopefully it will last a few years.

  • Sarah34

    I absolutely love it!
    My mouth feels so much relief and the customer service is spectacular. It is so much better than another company that I had tried previously. The fit is perfect for my mouth and I feel comfortable wearing it.

  • Mason Berger

    Been wearing mine for a few weeks and it’s been a life changer. My headaches and jaw soreness are gone! I’ve had many night guards through the dentist. I’ve paid a lot of money for these things. It’s nice to find an affordable option that still has the high quality I need. Thank you!

Free Shipping

We ship to you a kit with everything you need from the molding trays and putty, to the prepaid packaging the return it to us.

90 day guarantee

Try it out! If you’re not satisfied, you can always return the Mouthguard within 90 days for a full refund.

Save 20%

By entering coupon code "big spender", you save 20% on orders over $200.